84 Prof. C. G. Knott on Reflexion and Refraction of 



2. Distortional Wave Incident on the Plane Interface of two 

 Elastic Solids, of which the Rigidities and Compressibilities 

 are equal and the Densities as 2 to 3. 



(1) Incident Wave in the denser medium. 



0. 



B. 



B t . 



0'. B'. 



9. A x . 



9'. A'. 



0° 



14° 2' 

 26° 34' 

 45° 

 54° 24' 



1 

 1 

 1 

 1 

 1 



•on 



•01 

 •012 

 •01 

 1-00 



•989 

 17° -978 

 33° -912 

 60° -99 

 imaginary. 



•0 

 25° -005 

 51° -047 

 imaginary. 



•o 



31° -007 

 72° -029 

 imaginary. 



For all higher incidences there is total reflexion. 



(2) Incident Wave in the less dense medium. 



0. 



B. 



Bi. 



*'. 



B'. 



9. A x . 



9'. A. 



0° 



1 



•on 





•989 







14° 2' 



1 



•008 



11° 



•984 



25° -005 



20° -004 



26° 34' 



1 



•027 



21° 



•943 



51° -019 



39° -015 



45° 



1 



■01 



35° 



•99 



imaginary. 



imaginary. 



59° 2' 



1 



•01 



44° 



•99 





;) 



73° 18' 



1 



•088 



51° 



•912 







90° 



1 



100 



54° 



000 



" 



>> 



Similar peculiarities present themselves here. In case (lj, 

 for example, the refracted distortional wave accounts for 

 nearly all the energy until the critical angle is reached, when 

 the energy in the reflected distortional wave suddenly increases 

 to the final value unity. The comparative smallness in the 

 energies of the derived condensational waves is due to the 

 densities being taken as 2 to 3, that is, more nearly equal 

 than in the previous case. 



3. Behaviour of Waves at the Plane Interface of the Slate and 

 Granite, whose Elastic Constants are as given in the Table 

 on p. 68, the Densities being assumed to be equal. 



(1) Distortional Wave incident in the Slate. 



(p. B. 



B r 



f. 



B'. 



9. A v 



9'. A'. 



0° 1 



•016 





•984 







14° 2' 1 



•006 



11° 



•981 



22° -006 



20° -008 



26° 34' 1 



•001 



20° 



•960 



45° -005 



39° -032 



39° 25' 1 



•008 



29° 



•787 



90° 



62° -2 



45° 1 



•020 



33° 



•922 



imaginary. 



81° -058 



47° 56' 1 



•02 



34° 



•98 





90° 



59° 2' 1 



•085 



42° 



•915 



,, 



imaginary. 



73° 18' 1 



•144 



48° 



•856 







84° 17' 1 



•386 



50° 



•614 



" 



F> 



